1. Field of the Invention
The present invention relates to a process for the preparation of alkylene oxide adducts of active hydrogen compounds such as alcohols and to a process for preparing catalysts useful in such alkoxylation reactions.
2. Description of the Prior Art
Alkylene oxide adducts of hydrogen compounds find utility in a variety of products such as, for example, surfactants, solvents, chemical intermediates, etc. Typically, these alkylene oxide adducts are prepared by an addition or alkoxylation reaction in which an alkylene oxide, such as ethylene oxide, is reacted under suitable conditions with an organic compound, such as an alcohol, having one or more active hydrogen atoms. In particular, ethylene oxide adducts of aliphatic alcohols or substituted phenols having from about 8 to 20 carbon atoms have found widespread utility as non-ionic detergent components of cleaning formulations for use in industry and in the home.
The alkoxylation reaction produces a product mixture of various alkoxylate molecules having a variety of alkylene adducts (oxyethylene adducts). Because the number of oxyalkylene adducts or oxyalkylene groups effect the properties of the product, it is desirable to tailor the adduct number distribution of a given product mixture to its intended service. For example, it is known that in surfactant applications, an adduct with too few ethylene oxide molecules is not effective because of poor water solubility, while an adduct with too many ethylene oxide molecules is undesirable because surface tension reduction per unit mass decreases drastically with increasing molecular weight. Thus, as taught in U.S. Pat. No. 4,239,917, it is desirable, particularly for surfactant applications, to use ethoxylates or alkoxylates with a narrow or peaked distribution in the desired mole adduct range of from about 5 to about 10 alkylene oxide adducts per alkylate molecule.
PCT Application W085/00365 discloses an alkoxylation process which utilizes a calcium based catalyst to produce alkoxylation products having a narrow or peaked distribution of alkoxylation species.
U.S. Pat. No. 4,775,653 discloses a process for making another type of calcium based alkoxylation catalyst which utilizes aluminum alkoxides, the catalysts being useful in the preparation of alkoxylation products having a narrow or peaked distribution of the alkoxylation species.